1. Field of the Invention
The present invention relates to a color printer system and a printing method.
2. Description of the Related Art
Printers for a field of production printing (PP) that are used to achieve high-capacity and high-speed printing need to constantly perform printing at a high print speed and high resolution. Therefore, a challenge of the development of such printers is to transmit image data at a high speed. For example, a printer system for the PP field includes a raster image processing (RIP) server, an engine controller, and an engine.
An engine has been known which includes data transmission paths corresponding to five colors in five stations (Y (yellow), M (magenta), C (cyan), K (black), and a special color) (for example, see Japanese Patent Application Laid-open No. 2004-258512). A general color image is formed by using data of four colors, such as Y, M, C, and K, and a special color is not used to form a general color image. For example, the special color is a gold color, or clear toner, but is not limited thereto. The special color may be colors other than Y, M, C, and K.
In recent years, a technique has been examined which transmits uncompressed image data between the RIP server and the engine controller to increase a speed of the printer system.
In this case, a technique has been known in which image data are transmitted through high-speed transmission paths and the transmission paths for transmitting the image data are provided for respective colors, thereby transmitting the image data at a high speed (for example, see Japanese Patent Application Laid-open No. 2005-001340).
That is, Japanese Patent Application Laid-open No. 2005-001340 discloses a control method which fixedly allocates transmission paths for colors that are not used for printing to transmission paths for colors that are used for printing, in the printing mode in which the transmission paths for only one or two colors are used among the transmission paths for four (Y, M, C, and K) colors, in order to improve the transmission efficiency of image data (shorten the transmission time or improve image quality at the same transmission time). All of the transmission paths for Y, M, and C are allocated to K when printing is performed with only one color, that is, K, for example. When printing is performed with two colors, that is, Y and M, the transmission path for C is allocated to Y and the transmission path for K is allocated to M.
As another related art, an image transmitting method has been proposed which divides image data of a predetermined color among the image data of a plurality of colors into pixel units, periodically allocates a plural pieces of image data of the predetermined color, or the pixel units, which correspond to continuous pixels, to a transmission path for the image data of the predetermined color and the transmission paths for the image data of colors other than the predetermined color, and transmits the image data (for example, see Japanese Patent Application Laid-open No. 2006-279582).
However, in the related art, the transmission paths are allocated to all colors and image data is allocated to each transmission path and is then transmitted. Therefore, for example, even when printing is performed with four colors, that is, Y, M, C, and K, without using the special color, the time required to transmit the image data is the same as that when printing is performed with all of five colors. As a result, it is difficult to transmit image data at a high speed.